Laparoscopic surgery is a relatively new surgical method wherein the surgery is performed through several small incisions of an average length not exceeding 1/2", made in the patient usually in the abdomen. Because the need to make large incisions is avoided, both the operating and recovery time for the patient is significantly reduced, resulting in significantly less cost and physical trauma for the patient. For example, removing an inflamed gallbladder by traditional methods can cost about $10,000.00, require a 6" incision through the abdomen, and necessitate a four or five day stay in the hospital, followed by several weeks of painful recovery. Removal of a gallbladder using the laparoscopic method could easily permit the patient to return home the day of the surgery and result in a complete recovery in a few days.
Typically, laparoscopic surgery requires two or more small incisions, one of which is used to insert a laparoscope, a viewing instrument which allows the surgeon to see the patient's internal organs, or, alternatively, a specially designed camera through which images are transmitted to a nearby video screen. Use of a camera allows the procedure to be viewed by several surgical personnel simultaneously and to be recorded on video tape. One or more additional incisions are required so that other miniaturized surgical instruments such as cutting, grasping, suturing, and stapling devices can be used, if required. These instruments must be long and narrow to pass through the small incision and reach the appropriate organ located within the body cavity. Moreover, because these devices are difficult to sterilize, they usually must be disposable. Finally, the laparoscopic instruments should be constructed with a minimum number of small parts due to the risk of such parts breaking off and lodging in the patient's body.
The incisions are usually made with a trocar, a pointed instrument which punctures the abdominal wall and positions a tube or cannula in the abdominal wall so that the laparoscope or other instruments may be passed therethrough.
Surgical scissors, per se, designed specifically for laparoscopic surgery are known in the art, as is shown in U.S. Pat. No. 5,133,736 to Bales Jr. et al.
A key disadvantage of the Bales, Jr. device in particular, and the prior art in general, is that the cutting plane of the blades is fixed relative to the shaft of the instrument thereby limiting the maneuverability and reach of the instrument. In laparoscopic surgery the shaft of the instrument is slidably received in a trocar tube so there is limited ability to orient the cutting plane and orientation of the blades of the conventional instruments. Conventional laparoscopic scissors are effective at cutting tissue in planes passing through the axis of the instrument shaft. However, most organs and tissue in the human body are curved and oriented along a multiplicity of planes. The prior art scissors have been found ineffective at reaching and cutting these tissues. Moreover, attempts to cut tissue without first orienting the cutting plane of the blades perpendicular to the tissue has often resulted in peripheral damage to adjacent arteries and other vital structures.
Hence, there is a strong need in the art for a laparoscopic surgical instrument having scissors, tweezers, forceps or the like which can be easily oriented into various planes to cut or grip the targeted tissue.
U.S. Pat. No. 4,763,669 to Jaeger discloses a surgical instrument having an adjustable angle of operation. This instrument, designed for obtaining biopsies and the like, is not suitable for laparoscopic surgery as it requires a two-handed operation. During typical laparoscopic surgery, the surgeon will simultaneously use one hand to operate a gripping device and the other hand to operate a cutting device. Hence, there is a need for such instruments wherein the scissors or the like can be operated and reoriented with the same hand. Another disadvantage with the Jaeger device is that the angle adjustment takes place only in a single plane, namely, the plane in which the grippers open and close.
Another problem frequently encountered during laparoscopic surgery stems from the fact that the surgeon cannot directly see the organ or tissue which is being cut, but rather must view the subject matter through a single lens scope or on a video screen. Since the image being viewed is two-dimensional, it is difficult to gauge the depth of cut being made.
Accordingly, there is a need for a scissors (or other elements) which can be used in laparoscopic surgery in a manner to help the surgeon ascertain the depth of cut being made.